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тАО04-19-2006 12:13 AM
тАО04-19-2006 12:13 AM
hi all ,
i have an oracle database 10g and i want user not to block the table while doing update or insert and even with select using wildcards which takes a lot of time and others will wait till they finish.
i thought of a FIFO file , that i can create under Linux , where i can put all the transactions there and i will not lock the users from work ..
this fifo file , will have IN and OUT pointers , one is used to read and the other to write .
the transactions will be executed one by one and i will not have lock or freeze system .
can i achieve that with mkfifo in Linux ? how to write in a fifo file and later read from it and put in the database?
am i using the right commands and is it true what i thought doing ?
FIFO queues are stored in memory or on disk ?
if my server will reboot , the infos will be lost from the fifo file ?
tx for ur replies.
Regards
i have an oracle database 10g and i want user not to block the table while doing update or insert and even with select using wildcards which takes a lot of time and others will wait till they finish.
i thought of a FIFO file , that i can create under Linux , where i can put all the transactions there and i will not lock the users from work ..
this fifo file , will have IN and OUT pointers , one is used to read and the other to write .
the transactions will be executed one by one and i will not have lock or freeze system .
can i achieve that with mkfifo in Linux ? how to write in a fifo file and later read from it and put in the database?
am i using the right commands and is it true what i thought doing ?
FIFO queues are stored in memory or on disk ?
if my server will reboot , the infos will be lost from the fifo file ?
tx for ur replies.
Regards
Solved! Go to Solution.
- Tags:
- mkfifo
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тАО04-19-2006 02:18 PM
тАО04-19-2006 02:18 PM
Solution
A FIFO file, or "named pipe" can accomplish what you are attempting. However, it is a special file, a socket, and resides in memory. There is no stable storage, per-se. The file structure is used for IPC. If your system reboots, any data in the queue will be lost.
There must be a reading process and a writing process. FIFO's are sort-of half duplex. The first process writes to a FIFO and a second process reads from that FIFO. You normally do not write to and read from the same pipe. Instead, if you want 2-way communication between processes, you write to a first FIFO and read from a second FIFO.
Take a look at the fifo(4) man page.
It is possible to use non-blocking with a FIFO, but both the server and the client applications will need to keep watch on the communication path. Usually, only the reading server uses non-blocking.
The warning from the fifo(4) man page says it best:
Under Linux, opening a FIFO for read and write will succeed both in blocking and non-blocking mode. POSIX leaves this behaviour undefined. This can be used to open a FIFO for writing while there are no readers available. A process that uses both ends of the connection in order to communicate with itself should be very careful to avoid deadlocks.
Good Luck!
There must be a reading process and a writing process. FIFO's are sort-of half duplex. The first process writes to a FIFO and a second process reads from that FIFO. You normally do not write to and read from the same pipe. Instead, if you want 2-way communication between processes, you write to a first FIFO and read from a second FIFO.
Take a look at the fifo(4) man page.
It is possible to use non-blocking with a FIFO, but both the server and the client applications will need to keep watch on the communication path. Usually, only the reading server uses non-blocking.
The warning from the fifo(4) man page says it best:
Under Linux, opening a FIFO for read and write will succeed both in blocking and non-blocking mode. POSIX leaves this behaviour undefined. This can be used to open a FIFO for writing while there are no readers available. A process that uses both ends of the connection in order to communicate with itself should be very careful to avoid deadlocks.
Good Luck!
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тАО04-19-2006 05:58 PM
тАО04-19-2006 05:58 PM
Re: mkfifo
hi,
i prefer to use something that exists on the disk , cause maybe my server will doa reboot so my transactions will be lost if in memory.
do u have any other suggestion how to resolve my issue , someone told me about circular file ?
Tx for ur replies
i prefer to use something that exists on the disk , cause maybe my server will doa reboot so my transactions will be lost if in memory.
do u have any other suggestion how to resolve my issue , someone told me about circular file ?
Tx for ur replies
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